• Sleep Medicine and Psychophysiology
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• v.17 no.1
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• pp.11-15
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• 2010

Obstructive sleep apnea is a common sleep disorder that predominantly affects adult men than women. However, the prevalence in women increases with menopause dramatically. Menopause has long been described as a risk factor for obstructive sleep apnea. Recent large well-designed population studies support that menopause increases the risk for sleep-disordered breathing. The mechanism of that hypothesis is not yet clear. But, the decline in progesterone has been thought to influence the development of obstructive sleep apnea because progesterone is a respiratory stimulant and plays a protective role against sleep apnea. Increased visceral obesity and hypertension as major symptoms of metabolic syndrome are also associated with menopause and place women at increased risk for obstructive sleep apnea and other serious health problem. Hormone replacement therapy has been associated with a lower prevalence of sleep apnea. But, relative risk and benefits of hormone replacement therapy compared with other treatment options will require thorough consideration for each individual woman. Finally, attention should be drawn to the need for obstructive sleep apnea evaluation in perimenopausal and postmenopausal women.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.264-270
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• 2007

Obstructive sleep apnea syndrome (OSAS) is defined by sleep apnea with decreased oxygen saturation, excessive snoring with daytime sleepiness, and frequent awakening during the night time sleep. The present study was performed to investigate how apnea-hypopnea, that possibly causes breathing disturbance during sleep, can affect sleep pattern in patients with OSAS. We included 115 patients (92 men, 23 women) who underwent a polysomnography from January 2006 to May 2007. As the frequency of sleep apnea-hypopnea increases, the proportion of non-rapid eye movement (REM) sleep (p<0.001), and stage I sleep (p<0.001) increased, while that of stage II sleep (p<0.001), stage III and IV sleep (p<0.01), and REM sleep (p<0.05) decreased. Furthermore, sleep apnea-hypopnea was closely correlated with REM sleep (r=0.314, p<0.001), stage I sleep (r=0.719, p<0.001), stage II sleep (p=-0.342, p<0.05), stage III and IV sleep (r=-0.414, p<0.001), and REM sleep (r=-0.342, p<0.05). Stage I sleep could account for the 51% of the variance of apnea-hyponea. Our study shows sleep apnea-hypopnea affects sleep pattern in pattern with OSAS significantly, and the change of stage I sleep is the most important factor in estimating the disturbance of sleep pattern.

• Sleep Medicine and Psychophysiology
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• v.1 no.1
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• pp.60-67
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• 1994

Objectives: The Obstructive sleep apnea syndrome is characterized by snoring, observed apnea during sleep and excessive daytime sleepiness. The overnight polysomnographic recording is used to investigate patients with possible obstructive sleep apnea syndrome. But the overnight polysomnographic recording is time consuming, expensive, and labor-intensive. Recently in diagnosis of obstructive sleep apnea syndrome, several simple screening tests have been suggested. Methods: This study was performed to assess the probability of application of clinical features and the degree of oxygen desaturation as a screening test for the obstructive sleep apnea syndrome. The sensitivity and specificity of the self-report of clinical features including snoring, observed apnea during sleep, excessive daytime sleepiness and insomnia were tested. And the degree of oxygen desaturation measured by oximetry in 42 subjects were compared with the overnight polysomnographic recording results. Results: In the prediction of apnea index more than 5, the sensitivity of observed apnea during sleep, snoring, excessive daytime sleepiness and insomnia were 96.8%, 93.5%, 38.7%, 25.8% and the specificity of those clinical features were 182%, 36.4%, 100%, 72.7%, respectively. In the prediction of apnea index more than 5, the sensitivity and specificity of the combination of more than three self-report clinical features were 54.8% and 90.9%. The degree of oxygen de saturation and maximal apnea duration in the group of apnea index more than 5 were significantly different from those in the group of apnea index below 5(P<0.001). And the apnea index was significantly correlated with the degree of oxygen desaturation and maximal apnea duration(P<0.001). Conclusion: These results suggest that application of clinical features alone as a screening test for the obstructive sleep apnea syndrome is inadequate because of it's high rate of false positive and false negative results. The degree of oxygen desaturation measured by oximetry is possibly applicable to screening test and follow up evaluation of treatment efficacy for the obstructive sleep apnea syndrome.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.7
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• pp.605-608
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• 2011

In this study, OSA (the obstructive sleep apnea) periods were detected in patients with OSA during sleep because of the treatment was different according to the frequency and symptoms of obstructive sleep apnea. ANS (autonomic nervous activity) was changed by obstructive sleep apnea periods so we intended to detect the periods to care the obstructive sleep apnea patients. RR intervals, SDNN (standard deviation of normal to normal) and RMSSD (root mean square standard deviation) were calculated in time domain analysis and LF (low frequency), HF (high frequency), NHF (normalized high frequency), NLF (normalized low frequency) were calculated in frequency domain analysis of HRV (heart rate variability) with obstructive sleep apnea patients. In this paper, SDNN (standard deviation of normal to normal) of time domain analysis were decreased in the obstructive sleep apnea periods. And NLF and LF/HF ratio were increased and NHF (normalized high frequency) was decreased in the frequency domain analysis. The parameters can be used to treat obstructive sleep apnea patients by detecting the obstructive sleep apnea periods such as CPAP (continuous positive airway pressure).

• Child Health Nursing Research
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• v.10 no.4
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• pp.451-459
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• 2004

Purpose:　The purpose of this study is to identify how regular stimulation affects apnea of a premature infant. Method: This study was used a within-subjects design with repeated measure using GEE (General Estimating Equation) and had been conducted from July 1, 2003 to March 12, 2004. The subjects consisted of 11 apneic premature infants who had showed apnea more than twice for 12 hours. A regularly vibrating test lung was provided to the subjects to find how regular stimulation affects apnea. Result: From the result of regular stimulation for apneic premature infants, both the lowest SaO2 and the lowest heart rate at experimental period were found to be increased significantly. However, the decreased frequency of the apnea cases was not statistically effective. Conclusion: These findings indicate that regular stimulation for apneic premature infants could be effective on increasing both SaO2 and heart rate. Therefore, we suggest regular stimulation to be used clinically to heal apnea of premature infants.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.232-235
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• 1997

Apnea refers to episode of apnea (or not breathing) lasting more than 10 seconds that occur while sleeping. These episodes, whitch can occur hundreds of times per night, may transiently awaken resulting in fragmentation of sleep. Although the precise cause of Sudden Infant Death Syndrome(SIDS) are still unclear, there is evidence to suggest that hypoxaemia may be a contributory actor. Transcutaneous oxygen monitor can be used, but it is very difficult to use or baby stayed at home. In this reason, monitors whitch is easy or deal with are reqiured. In 1972, Steinschieder reported that two of the five infants noted to have apnea lasting or more than 20 seconds later died of SIDS episode, he also suggested that home monitoring or neonates should be used or managing apnea at home. Transthoracic electrical impedance technique is used or acquiring respiration waveform and detecting episode of apnea state. Transthoracic electrical impedance measurements have been made from the human trunk over the frequency range 9.6KHz to 614KHz. We conclude that application of impedance technique or detecting apnea state is proper or neonates.

• Journal of Biomedical Engineering Research
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• v.34 no.2
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• pp.97-103
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• 2013

This paper proposes a new algorithm for sleep apnea detection based on stroke volume. It is very important to detect sleep apnea since it is a common and serious sleep-disordered breathing (SDB). In the previous studies, methods for sleep apnea detection using heart rate variability, airflow and blood oxygen saturation, tracheal sound have been proposed, but a method using stroke volume has not been studied. The proposed algorithm consists of detection of characteristic points in continuous blood pressure signal, estimation of stroke volume and detection of sleep apnea. To evaluate the performance of algorithm, the MIT-BIH Polysomnographic Database provided by Phsio- Net was used. As a result, the sensitivity of 85.99%, the specificity of 72.69%, and the accuracy of 84.34%, on the average were obtained. The proposed method showed comparable or higher performance compared with previous methods.

• Sleep Medicine and Psychophysiology
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• v.17 no.2
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• pp.69-74
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• 2010

Obstructive sleep apnea syndrome is associated with significant cardiovascular morbidity and increased mortality. However, it was controversial whether obstructive sleep apnea syndrome could cause pulmonary hypertension. The controversy was resolved by several studies that have shown pulmonary hypertension in 20% to 40% of patients with obstructive sleep apnea syndrome without underlying other cardiopulmonary diseases and reductions in pulmonary arterial pressure in patients with obstructive sleep apnea syndrome after treatment with nocturnal continuous positive airway pressure. Recent studies provide strong evidence for endothelial dysfunction in obstructive sleep apnea syndrome and pulmonary hypertension. Endothelin-1 is a 21 amino acid peptide with diverse biologic activity such as highly potent vasoconstrictor and mitogen regulator that may play a key role in obstructive sleep ap-nea syndrome and pulmonary hypertension. Continuous positive airway pressure therapy is moderately effective in reducing pulmonary arterial pressure. Further researches are needed to assess the therapeutic efficacy of pharmacologic therapy with agents that inhibit the action of endothelin-1 in obstructive sleep apnea syndrome patients with pulmonary hypertension.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.17-23
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• 2017

In this paper, we implemented a respiration measurement system consisting of piezoelectric sensor, respiration signal processing device, and a viewer on a notebook. We tried an experiment for measuring respiration and detecting sleep apnea syndrome when a subject lay on a bed. We applied the respiration measurement algorithm to sensor data obtained from four subjects. In order to get a good graph shape, data manipulation methods such as moving averages and maximum values were applied. The window size for moving average was chosen as N=70, and the threshold value for each subject was customized. In this case, the proposed system showed 96.0% accuracy. When the maximum value among 90 data was applied instead of moving average, our system achieved 95.1% accuracy. In an experiment for detecting sleep apnea syndrome, the system showed that sleep apnea occurred correctly and calculated the average interval of sleep apnea. While infants or the elderly as well as patients with sleep apnea syndrome are lying down on a bed, our results are also expected to be able to cope with some accidental emergency situation by observing their respiration and detecting sleep apnea.

• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.77-89
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• 1996

Data collected to date indicate that sleep apnea syndrome is a risk factor in the development of cardiovascular dysfunction such as systemic hypertension, cardiac arrhythmias, pulmonary hypertension, right heart failure, angina, myocardial infarction, and stroke. Several reports suggest that untreated patients with sleep apnea syndrome have a higher long-term mortality than treated patients and than normal subjects. But there are many controversies concerning the treatment of sleep apnea syndrome, and there is no universally accepted standard for effective treatment. We reviewed the current approaches and options in the medical treatment of sleep apnea syndrome.